The hottest month in Hong Kong Island is July when the average maximum temperature is 33°, average temperature is 30° and average minimum temperature is 27°.
The coolest month in Hong Kong Island is January when the average maximum temperature is 19°, average temperature is 16° and average minimum temperature is 14°.
The longest days in Hong Kong Island are in June, with an average of 13.5 hours of daylight per day. December has the shortest days with an average of 10.8 hours of daylight per day.
The sunniest days in Hong Kong Island are in April which has the most hours of sunshine per day with an average of 8.8 hours of sunshine per day, making it a sunny month with few clouds. August has the least sunshine with an average of 4.7 hours of sunshine per day, making it a sunny month that is overcast at times.
The ultraviolet index is the highest in May when it reaches 13.2 and lowest in December when it reaches 6.7.
An ultraviolet index reading above 11 indicates an extreme risk of harm from unprotected sun exposure. Unprotected skin risks burning in less than 10 minutes. Take all precautions because unprotected skin and eyes can burn in minutes. Tanning will be safest before 10am and after 4pm but only with a good application of sun screen. For those with sensitive skin stay in the shade and wear protective clothing, a wide-brimmed hat, and UV-blocking sunglasses. Generously apply broad spectrum SPF 30+ sunscreen every 2 hours, even on cloudy days. Watch out for relections from water that may increase ultraviolet exposure.
The warmest sea water temperatures in Hong Kong Island are found in August when they peak at 29° and lowest in February when they dip to 21°.
The sea is best for swimming between May and December when the temperature is above 25° which is warm and pleasant for relaxing and swimming for long periods.
The wettest month in Hong Kong Island is June with 45.6cm of rain and the most days of rain with 21.4 days with some rain, a very wet time to visit the beach.
The driest month in Hong Kong Island is January with 2.5cm of rain and December has the fewest days of rain with 6.8 days with some rain, a dry time to visit the beach.
The most humid month in Hong Kong Island is July with a dew point (an indicator of humidity) of 26° which is very uncomfortable and fairly oppressive unless you are on a beach. At night you would most likely require airconditioning.
The least humid month in Hong Kong Island is January with a dew point of 12° which is very comfortable.
The most windy month in Hong Kong Island is April when the average maximum windspeed is 32kmh and the average wind speed is 19kmh.
The least windy month in Hong Kong Island is October when the average maximum windspeed is 26kmh and the average wind speed is 16kmh.